Woven fabric webbing is used to make a wide variety of products, including cargo lifting slings, safety harnesses of various types, and the like. In applications where abrasion resistance is particularly required, such as for cargo lifting slings, it is known to weave yarns of cut- and abrasion-resistant material into the edges of the flat woven webbing to protect it in use.
For example, Kelen et al U.S. Pat. No. 5,167,263 shows weaving a polyamid yarn or monofilament into the edges of webbing for similar purposes. Hammersla U.S. Pat. No. 4,856,837 shows a yarn made up of strands comprising a core, e.g., a polyester cord, covered by a continuous sheath of a cut-resistant resin such as “Hytrel” thermoplastic polyester elastomer. A number of such yarns are woven into the opposed edges of the flat webbing and used without performance of any treatment intended to alter the properties of either the core or the sheath.
Golz U.S. Pat. Nos. 5,219,636 and 5,419,951 show a yarn for similar use comprising a number of filaments, each filament in turn comprising a monofilamentary core of a first material, typically polyester, covered by a continuous, solid sheath of a second material; the material of the sheath is to have a lower melting point than the material of the core. Exemplary sheath materials are nylon-6, polypropylene, or polyethylene. After these yarns are woven into the webbing, the assembly is heat treated to a temperature such that the material of the sheath melts, whereupon the sheaths of the several filaments adhere to one another, forming a solid mass with the core members embedded therein upon cooling.
While webbing made according to the teachings of both the Hammersla and Golz patents has been commercially successful, further improvement is always to be sought.